This invention relates to power drives, and in particular to an improved lightweight portable power drive.
Power drives are in wide use in the plumbing trade. These devices consist essentially of a power source such as an electric motor, a rotatable member, gearing for connecting the power source to the rotatable member, and a casing. One or two torque arms are frequently included for supporting tools used with the drive. An example of a commercially available power drive is sold by The Ridge Tool Co., Elyria, Ohio, as its Model No. 300 Power Drive, and is described in Operator's Manual No 300-M-677 (940-600-015), hereby incorporated.
Generally, the rotable member is a chuck. A length of pipe held in the chuck is supported and rotated by the drive while the pipe is worked on, for example, by a hand-held pipe cutter, reaming tool, or die head. The chuck or other rotatable member may also be used as a power source for other devices, such as geared pipe threaders.
A power drive of this type is generally mounted on a stand of some sort. A commercially available tripod stand sold by The Ridge Tool Company, as its Model No. 1206, includes a mounting plate carried on a foldable tripod. Mounting pads on the base of the power drive allow the drive to be bolted onto the tripod to produce a solid, convenient unit.
Presently known power drives of this type are too heavy for easy portability and too expensive for small plumbing shops and individual users.
Lightweight portable power drives are also known. They are used for most of the same purposes as the previously described drives. A commercially available portable power drive is sold by The Ridge Tool Company as its Model No. 700 Portable Power Drive, and is described in Operator's Manual No. 700-PD-569-R5 (940-707-010), hereby incorporated. These drives, however, are strictly hand-held devices. They are less convenient to use, and they lack many of the features of the larger stand-mounted drives. They do not hold a length of pipe as do the larger stand-mounted drives, but connect to and rotate the die head while the pipe is secured by some other means such as a pipe vise.